There are many possible sources of noise in an electric circuit. For example, the transmission of data through a circuit requires electric current, which creates an electromagnetic field. The electromagnetic field may interfere with other signals in the circuit, thus resulting in electromagnetic interference (EMI). Another possible source of noise is contact noise, which occurs at a point of contact when a current source is turned on/off with a switch. This is a common phenomenon in a power supply. Noise may also be caused due to an electrostatic discharge, also referred to as a surge. Regardless of the source, noise is a factor that needs to be considered in most electric circuits.
Various suppression techniques are used to address noise, for example with the use of shields and filters. Sometimes noise suppression techniques are used directly inside the electric circuit and considered during the design phase. This is usually done to ensure that the noise does not interfere with circuit components and functions within the system. Sometimes noise suppression techniques are used post-design, for example to ensure that a product containing the electric circuit does not emit noise that could interfere with other equipment in the vicinity of the product.
There are certain instances where noise suppression has a negative impact on the electric signal, for example in certain types of audio or video signals. Indeed, suppressing noise may affect the sound dynamic of an audio signal or the vibrancy of the colors of an image, thus affecting the user experience. There is therefore a need to improve on existing noise suppression techniques.